Expert networks give investors an edge

But regulators say some have stepped over the line

E ven on a Saturday, the conferences that Dr. Leslie Fang attended in New York for MedaCorp, a Boston firm that provides investors with industry insight from medical professionals, were packed.

A renowned kidney specialist and physician at Massachusetts General Hospital, Fang with other prominent physicians would dish on the latest treatments and research - information fund managers in the audience hoped would provide an edge when investing in health care. Still consulting intermittently for MedaCorp, Fang is amazed at the people who interrupted weekends for the briefings.